This invention pertains to a radar tracking system and display, and in particular relates to such a system with a simplified display that, in addition to radar echo signals, displays plays additional information such as target azimuth and/or altitude.
There exists, of course, various designs of complex radar systems which provide a variety of information about radar targets. Typically, such radar systems are large and expensive, and are swept type systems and incorporate a complex display, such as a CRT display. In addition to such large and expensive prior art radar systems, there does exist small and relatively inexpensive radar units. One such unit is that sold under the name "Whistler Radar". Such a small radar unit is generally intended to be hand held, or at least manually swept. Target information in the "Whistler" radar is given in audio form. The operator dons earphones and scans the horizon in the direction of interest. When no target is detected by the radar beam, the Whistler radar unit is silent. A sharp whistle sound announces that a target is within range. Target range or distance to the target is determined by the pitch of the sound, and, for targets that are relatively close to the Whistler radar unit, a meter is provided on the unit and the meter pointer also serves as an indication of range.
A radar system such as the "Whistler" unit described above is useful but has limitations. For example, it requires a considerable amount of experience before an operator is able to translate the varying sounds of the unit to range or distance information. Furthermore, the "Whistler" unit only provides a real time target indication with respect to the direction in which it is pointed; it is therefore difficult to obtain an overall indication of e.g. the configuration of a shoreline or the like. Additionally, it would be difficult or impossible for an operator with a hearing impairment of any kind to operate the "Whistler" type radar unit.
While it is clear that small inexpensive radar units such as the "Whistler" radar unit have marine, law-enforcement and military applications, to mention a few, it is also clear that such units would have even more value if they provided additional information, and/or had a better arrangement for interpreting the radar echo information.